Valve stem packing



BY Ggfywf f Q 9, i939- V D. D. ROBERTSON I-:r AL. 2,157,366

VALVE STEM PACKING Original Filed Dec. 24, 1935 A,2 Sheets-Sheet l INVENTORSI/` ewz .a 1975er 6017.

ORN E Y 4 ;J/-t-MESS',* 4 I BY George. L, Brig 5 May 9, 939- D. D. ROBERTSON ET Al. 2,157,866

' VALVE STEM PACKING Original Filed Dec. 24, 1955 2 Sheets-Sheet 2 A Il 4e J2 l j,

lg/61' ZZ l ZZ Ji; 9 I Z7 /5 N l .ZZ I l "ZZ INVENTORS, y.Z6

Del mar' D. Robersorz A'T EY.

Patented May 9, 1939 PATENT @FFME VALVE STEM PACKING Delmar D. Robertson, Lansdowne, and George L. Briggs, Bryn Mawr, Pa., assignors to Wilkening Manufacturing Company, Philadelphia, Pa., a corporation of Delaware Application December 24, 1935, Serial No. 55,980 Renewed August 23, 1938 Claims.

The present invention relates to packing or sealing means and it relates more particularly to valve-stem packing for use in internal ccmbustion engines for eiecting a seal between the reciprocatory valve stem and the stationary valve stem guide.

An object of the present invention is to provide enifcient and durable packing or sealing means intermediate the valve stem, the valve stem guide in an internal combustion engine or the like, which will effectively seal against the passage of gases and liquids through the greater or lesser clearances commonly present between the valve stem and the guiding aperture in which the valve stem is slidably mounted for its reciprocatory movement.

A further object of the present invention is to provide valve stem packing or sealing means of the character stated, which, while effectively and durably sealing between the valve stem and its retaining guide aperture, will nevertheless not impose any undue friction upon the valve stein, and which will not materially increase the resistance of the valve stem to its operative movements, and which will not in any way disturb, alter or affect the spring tensioning of the valve which is predetermined in the original design of the engine (as for instance, where the device of the present invention is applied to engines initially designed and built without any valve stem packing or sealing means.) With the above and other objects in View which may appear more fully from the following detailed description and accompanying drawings, the present invention consists of valve-stem packing means comprising a certain novel combination oi retaining means and sealing means asso- 'ciated with the valve stem guide in a novel manner whereby the valve stem packing or sealing means may be maintained in operative relation to the valve stem guide without any supplemental or auxiliary devices, such as springs, screws, etc.

The present invention further consists of a certain novel co-relationship between valve stem packing means and valve stem guide, whereby a positive interlocking engagement is obtained between the valve stem guide and valve stem packing or sealing means without external aid or without the aid of external fastening means or retaining means. The present invention further consists oi certain novel features and details of construction in a valve stem packing cage and certain nove-l co 1 bination of valve stem sealing means therewith.

The present invention further consists of other novel features and details and rel'ationslfiips, which may appear more fully'in the following detail-ed description and accompanying drawings.

YFor the purpose of illustrating the invention, there is shown in the accompanying drawings one form thereof which is at present preferred, since the same has been found in practice to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which the invention consists can be variously arranged and organized and that the invention is not limited to the precise arrangement and organization of the instrumentalities as herein shown and described.

In the accompanying drawings in which like reference characters indicate like parts:

Figure 1 represents a fragmentary perspective view, on a much enlarged scale, oi the valve-stem packing and sealing means embodying the present invention, with part of the packing or sealing means broken away and shown in section.

Figure 2 represents a fragmentary perspective view of a sealing means adapted to be substituted for that shown in Figure 1, but of somewhat different construction.

Figure 3 represents a horizontal sectional View taken on the line 3-3 of Figure 6, the scale being intermediate that of Figure 1 and that of Figure 6.

Figure 4 represents a section on line l-- of Figure 3.

Figure 5 represents a perspective View oi the retaining cage alone, on a somewhat smaller scale.

Figure 6 represents a fragmentary vertical sectional view of a cylinder block which contains the valve stem guide and valve shown on approximately full scale and showing the valve-stem packing or sealing means of the present invention partly in section; the parts of the internal combustion engine shown, being intended merely as representations of any conventional engine construction.

Figure 'I represents a section similar to that shown in Figure 6, though on a somewhat smaller scale, indicating a method by which the valvestem packing or sealing means of the present inventionmay be applied to the valve-stem guide.

According to the present invention, retaining means designated generally by the numeral l and which may be called a cage, is provided, having an upper portion 8 for receiving and confining a generally annular sealing member s or 9m and having lower engaging means ii) adapted for retaining engagement, gripping engagement or interlocking engagement with a terminal portion i l of any valve stem guide i2 (either the upper terminal portion or the lower terminal portion).

The upper portion 8 is formed generally with a side wall l2, which is preferably of a more or less cylindrical form, and an upper transverse terminal Wall I3 which may be more or less right angularly disposed with respect to the side wall l2. A central aperture I4 is provided in the terminal wall I3, of a diameter slightly larger than the diameter of the particular valve stem i5 which it is adapted to lit and which it is adapted to surround; the difference in diameters being such dilerence as will form a suitable working clearance together with such tolerances as may be necessary to accommodate the necessary manufacturing facilities or methods which may be employed for the production of the member l.

The inner diameter of the more or less cylindrical side Wall I2 may be made more or less the same as the diameter of the end surface IG against which the sealing member 9 is adapted to bear, although some latitude in this regard is possible.

The lower guide-engaging portion it of the retaining member 'l is (in the particular embodiment herein shown) composed of a plurality of circumferentially distributed fingers I "l which may, as in the embodiment herein shown, be arranged as a part of the same (more or less) cylindrical surface, so that such fingers will in transverse Crosssection be shaped like the arc of a circle, and will lie generally in the arc of the same circle. The fingers Il are preferably arranged as fragmentary parts of a. more or less cylindrical surface of somewhat larger diameters than the diameter of the side wall I2, with a slight transverse flange-like portion I8 intermediate of and inter-connecting the side wall i2 with the ringers or legs Il.

The free terminals of the fingers or legs il are curved inwardly to form slight inwardly extending claw-like flanges I9, which are arranged in generally concentric or coaxial relationship to the fingers or legs Il as Well as to the side-wall I2 and aperture I4 and which in transverse cross-section, however, may be slightly curved and slightly inclined, as indicated, for instance, in Figures l, 3 and 4. The terminal corners 2Q of the slight claw-like anges i9 are made suitably sharp, so that these corners or rather the slight edge formed in these corners may serve to cut the annular groove 2| into the side-wall of the valve-stem guide I2 by relative rotation of the cage 'I and valve stem guide I2 in a man* ner described more in detail hereinafter.

According to another phase of the present invention, suitable projection (or indentations) 22 may be provided either on the side-wall I2 or on the terminal wall I3 or some other part of the cage whereby interlocking engagement may be effected between the cage l and a suitable turning tool 23. By providing the slight ribs 22 in the general form indicated in the embodiment of the invention herein shown, the turning tool 23 may be in the form of a socket wrench as indicated in Figure 7, having any suitable handle 2d, whereby the cage 'I may be turned manually r otherwise after the socket Wrench has been superimposed upon the ribbed portion of the cage; the series of circumferentially distributed ribs deiining between them arectangle,trangle or any other suitable polygon, and the socket wrench being similarly formed in a manner conventional in socket wrenches.

In the particular embodiment shown, the ribs 22 also serve to reinforce the cage and particularly to reinforce the legs Il at their upper ends by providing a slight transverse bracing across the slight flange I8 directly above each leg so as to minimize deflection of the legs at the place where they join the rest of the cage and to conne such deflection as may be caused in the leg, to the body part of the leg.

The cage 'l is preferably stamped and formed out of a sheet of steel of suitable thickness and grade, by means of suitable stamping and forming dies and is then preferably tempered to give the legs Il a desired resiliency or springiness so they will function as spring fingers and also to give the slightcutting edges suilicient hardness and permanence to enable them to cut the annular groove 2l in the side wall of the valve-stem guide. Thus, the slight cutting edges 20 should be suiiicic-ntly harder than the metal of which the valve stem guide is formed, that the cutting edges E will cut a clean groove 2! in the valvestem guide when the cage is rotated in relation to the guide.

The valve stem packing or sealing means of the present invention may be applied to the valve stemguide by the means generally shown in Figure '7; including the socket wrench-like tool 23 and the guiding pin 25 having a suitable head 26. The diameter of the pin 25 is such as to permit a neat sliding fit in the bore 2l of the valvestein guide I2 and the head 25 being sufliciently small to repose within the recess 28 of the socket wrench 23. The cage 'l having the generally annular sealing member 9 assembled therein, is then threaded onto the pin 25 and the resultant assemblage is then applied to the desired end of the valve-stem guide (from which the valvestem has preferably been removed) in a manner shown in Figure 6, and the Wrench 23 is then applied the top of the cage and the cage forcibly pressed onto the valve-stem guide in an axial direction so as to spread the legs I'I of the cage (against the spring tension inherent in said legs) until the generally annular sealing members 9 is firmly pressed in an axial direction between the terminal surfaces E81 of the valve-stem guide and the inner surface of the terminal Wall I3 of the cage. When the cage has been so superimposed upon the valve-stem guide to this extent, then, without releasing the axial pressure upon the cage, the cage is. turned several revolutions, thereby causing the slight cutting edges 20 to cut an annular groove into the outer surface of the valve-stem guide, and at the same time, ernbedding the claw-like anges lil of the springlegs il in the groove thus formed, and establishing a generally permanent interlocking engagement between the cage and the valve-stem guide, with the generally annular sealing member 9 under axial compression. When the groove 2| is of suiiicient depth, the wrench 23 is removed and the pin 25 is removed, and in place of the pin 25, the valve-stem I5 is reinserted into the position shown in Figure 5, or as also shown in Figures l, 2, and 3.

If desired, the periphery of the claw-like flanges i9 may be slightly relieved from the cutting corners or cutting edges 2i), as for instance, by shaping such peripheral edges on a slightly smaller radius than the radius of the valve stem guide which the cutting corners or edges 20 are intended to cut, so that the generally circular peripheral portions of the claw-like flanges which trail the cutting edges 2i? when the gage is rotated, will be slightly relieved and thus permit of a more effective cutting operation. So too, if desired, a slight backward rake may be provided on the cutting corners, also to facilitate the cutting operation.

The claw-like flanges I9 may be disposed generally at a right angle to the spring legs I1 or at a right angle to the axis of the device, or they may be slightly inclined, as indicated particularly in Figures 1, 3, 4 and 6, whereby the axial compression on the generally annular sealing member 9 may be increased slightly as the depth of the groove is increased, by Virtue of the fact that the claw-like flange will give the entire cage a slight camming action in an axial direction, tending to' pull the cage further onto the valve stem guide as the depth of the groove is increased from'the initial out to the nal depth of the groove.

The sealing member S may either be of a continuous or unbroken annulus, as for instance, formed by molding or by stamping or otherwise cutting the mem'ber s out of a solid piece of material, or the member 9 may be formed discontinuously in the generalmanner of split packing rings, and perhaps formed of va continuous strip or band of material curved into a generally annular shape and with its ends in more or less abutting relation to each other, and also suitably beVelled or inclined so as to form, in effect, a generally continuous annulus surrounding the valve stem l5.. However formed, the outer diameter is made generally to conform to the inner diameter of the side wall l2 of the cage, while the inner diameter is made generally to conform to the diameter of the Valve-stem l5.

The sealing member is formed of a more or less resilient material preferably including a fibrous body and a non-brous binder. In one embodiment of the present invention, the sealing member 9 may be formed of a body of cotton or a body of asbestos or a mixturel of the two, with a non-fibrous binder which may impregnato the iibrous body to a greater or lesser depth either completely or partially.

If the body is formed of a strip of material, then a suitably braided or even a suitably twisted textile structure or strand may be used, formed of cotton or of asbestos or a mixture of the two, while if the member is to be formed without any interruption, that is, without any split in its circumference, then it may be cut out of a sheet of woven or other textile formation of suitable thickness, either single ply or double ply, or multi-ply, formed of common asbestos or a mixture of the two, or it may be molded or matted or felted out of these respective fibres or mixtures of the same. Y'

The annular sealing member may be impregnated at any stage in its formation or after the annulus is finished, with any suitable oil-resistant binding material which preferably has suitable resiliency or at least which will not altogether destroy the resiliency inherent in the iibrous body of the member 9. For such binding material, a resilient and oil-resistant amorphous organic material may be used, such as the synthetic organic materials known in the trade 'under the trade-marks or trade names Duprene and Thiokol, which are generally regarded as artiiicial or synthetic rubber but which, while possessing the generally amorphous and resilient characteristics of rubber, do not respond to the solvent or deteriorating action of oils and gasoline in the same manner as rubber does, and in fact, resist oil and gasoline to a substantial extent, and also resist heat to an extent suitable for use in the valve-stem packing or sealing means of the present invention.

The impregnation may be, as stated, either throughout themass of the fibrous body or it may be partially through such mass, and the proportions of binder and brous body may vary in the finished member 9.

In the formation of the sealing member 9, graphite or other anti-friction material may be incorporated either in the fibrous body or in the binding material, or it may be applied to the surface of the sealing member 9 after the same has 'been formed, thereby to minimize friction between the bore of the member 9 and the surface of the valve stem I5.

In the sections of the member 9 shown in Figures 1, 2, 3, 5 and 6, variant formations are shown for the member 9, because, as stated, this member 9 may be formed of successive superimposed plies of woven, knitted or other textile formations (of cotton, or asbestos, or mixtures) as indicated generally in Figure 3, or may, be formed of felted brous masses, as indicated generally in Figures 5 and 6, or may be formed of braided, twisted, tubular woven or knitted, or i'iat woven or knitted and subsequently rolled textile strands or bands, (one form of which is illustrated in Figure l) which may be variously impregnated or filled with the binding material as mentioned. So too, the member 9 may be formed of the resilient and oil-resistant amorphous organic material mentioned, without any fibrous material contained therein, or with the fibrous material mixed and compounded in the material itself, while the same is .in a plastic state and before it is molded or formed to shape.

The valve-stem packing or sealing means of L the present invention is highly eicient and effective over a long period of time and under all operating conditions, as it is found that a good sealing contact is maintained between the bore of the sealing member 9 and the surface ofthe valve-stem i5, without any appreciable wear and also without the development of any appreciable looseness between such member 9 and Valve stem l5, and also that a substantially permanent contact is maintained between the end of the valvestem guide and the juxtaposed surface of the sealing member 9. The permanence of these sealing contacts. may be due partly to the tension initially set up in the spring legs il, and due partly to initial compression under which the annular sealing member Q is placed, and perhaps also due to the slight tendency of the fibrous body to swell and also due to the absence of any substantial wear in the bore of the member. By the Valve-stem packing and sealing means of the present invention, the passage of oil from the crank case into the combustion chamber or into the gas intake passageways of the cylinder head is minimized, and also the intake vacuum in the combustion chamber is maintained at the maximum, because of the seal effected around the valve stem.

In the particular illustration herein shown, the valve-stem packing and sealing means of the present invention is .shown applied par"cularly to the end of the valve stem guide nearest the combustion chamber, although it is to be understood that the valve stem packing and sealing means of the present invention may also be applied to the other end of the Valve-stem guide.

The present invention may be embodied in other speciiic forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing de-A` scription to indicate the scope of the invention.

Having thus described the invention what is hereby claimed to be new and desired to be secured by Letters Patent is:

l. Packing means for sealing the engaged surfaces of a Valve stem and a guide therefor, said means comprising a metal cage having a portion forming a chamber at one end, a sealing member within the chamber adapted to engage the end of said guide and surround said stem, and a plurality of legs extending in a generally axial direction irom chamber-forming portion of the cage, each leg terminating in a radially inwardly directed claw having a hardened cutting edge, and all of said cutting edges being substantially concentric and co-planar, whereby rotation oi the cage on the guide will rout a claw-receiving groove in the guide.

2. Packing means for sealing the engaged surfaces of a valve stem and a guide therefor', said means comprising a steel cage having a portion forming a chamber at one end, a sealing member within the chamber adapted to engage the end of said guide and surround said stem, and a plurality of legs extending in a generally axial direction from said chamber-forming portion of the cage, each leg terminating in a radially inwardly directed claw having a steel cutting edge, and all of said cutting edges being substantially concentric and co-planar, whereby rotation of the cage on the guide will rout a claw-receiving groove in the guide.

3. Packing means for .sealing the engaged surfaces of a valve stem and a guide therefor, said means comprising a metal cage having a portion forming a chamber at one end, a sealing member within the chamber adapted to engage the end of said guide and surround said stem, and a plurality of legs extending in a generally axial direction from said chamber-forming portion of the cage, each leg terminating in a radially inwardly directed claw having a hardened cutting edge, all of said cutting edges being substantially concentric and co-planar, whereby rotation of the cage on the guide will rout a claw-receiving groove in the guide, and said cage having a noncircular cross-sectional shape adapted to receive a socketed tool for turning the cage on the guide and having a radial shoulder for receiving axial thrust of said tool.

4. A self-interlocking cage for operatively retaining a valve stem packing in position against an end of a valve stem guide, said cage including a chamber portion for receiving said packing, and a plurality of legs extending in a generally axial direction from said chamber portion and each terminating in an inturned claw-like iange portion provided with a cutting edge adapted to groove said guide upon rotation of said cage thereon, said flanges being inclined relative to the axis of said cage thereby to advance said cage axially on said guide as the depth oi the groove is progressively increased.

5. A self-interlocking cage for operatively retaining a valve stem packing in position against an end of a valve stern guide, said cage including a chamber portion for receiving said packing, and a plurality of radially resilient legs extending from said chamber portion, said legs each terminating in an inturned terminal guide-cutting portion struck along a smaller radius than the radiaus of the correspondingvalve stem guide portion to provide two cutting corners with a relieved portion therebetween, whereby said cage will readily groove and interlock with said valve stem guide when rotated thereon in either direction.

6. A cage for operatively retaining a valve stem packing in position against the end of the valve stem guide, said cage including a chamber portion for receiving said packing, radially resilient legs extending from said chamber portion and having inturned terminal portions each interlocking engageable with a recess on the exterior of said valve stem guide, a portion of generally non-circular cross section adapted to receive a socketed tool, and a shoulder portion for receiving axial thrust of said tool.

7. In an apparatus for grooving the outer surface of a valve-stem guide, a cage having a portion adapted to radially and axially confine a generally annular sealing member, said cage having radially resilient iingers adapted to extend along the said guide and having terminal porvtions provided with cutting and engaging means, and said cage member having circumferentially distributed ribs adapted to be engaged by a tool and further having a shoulder adapted to be engaged by said same tool whereby said cage may be turned by said tool while axially thrust on said valve stem guide.

8. In an apparatus for generally permanently assembling a sealing means on a valve-stem guide, a cage member adapted to radially and axially confine a generally annular sealing member, said cage having radially resilient fingers adapted kto extend along the valve-stem guide and having terminal portions provided with cutting and engaging means, said cage having circumierentially arranged means adapted to be engaged by a turning tool, whereby said cage may be turned by the tool to groove the surface of the valve-stem guide and to engage the cage therewith while exerting axial pressure on the cage.

9. n an apparatus for generally permanently assembling a sealing means on a valve-stem guide, a cage adapted to radially and axially confine a generally annular sealing member, said cage having radially resilient iin-gers adapted to extend along the valve-stem guide and having ternnal portions provided with cutting means and engaging means, said cage also having means adapted to be engaged by a turning tool and having a shoulder adapted to be engaged by the tool to exert axial thrust on the cage during the turning movement, whereby said cage may be turned by said tool while being axially thrust onto said valve stem guide, thereby to groove said guide and to engage the cage therewith.

10. In an apparatus for generally permanently assembling a sealing means on a valve-stem guide, a cage adapted to radially and axially conne a sealing member and having radially resilient fingers adapted to extend along the valve-stem guide and having terminal portions provided with cutting means, said cage having circumferentially distributed ribs adapted to be engaged by a turning tool, said cage also having a shoulder adapted to be engaged by the same tool for exerting axial pressure on the cage during the turning movement whereby said cage may be axially thrust against and turned on said guide, thereby to groove the guide and engage the cage therewith,

DELMAR D. ROBERTSON. GEORGE L. BRIGGS. 

